Method and apparatus for forming arch tubes



Jialy 28, 1931. c. A. HENRY ET AL 1,816,213

METHOD AND APPARATUS FOR FORMING ARCH TUBES Fi led April 29, 1929 5 Sheets-Sheet 1 /Z KM mi July 28, 1931.

c. A. HENRY ET AL] METHOD AND APPARATUS FOR FORMING ARCH TUBES July 28,1931. c. A. HENRY ET AL 1,315,218

METHOD AND APPARATUS FOR FORMING ARCH TUBES Filed April 29, 1929 5 Sheets-Sheet a 'fzzvcfzz arr Gian 129.11%

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METHOD AND APPARATUS FOR FORMING ARCH TUBES I Filed April 29. 1929 s sheets-sheet 4 July 28, 193.1.

C. A. HENRY E'I AL METHOD AND APPARATUS FOR FORMING ARCH TUBES Filed April 29, 1929 5 Sheets-Sheet 5 fizz/024 5715 rslfi Carl/Z 050/557 Patented July 2 8, 1931 UNITED STATES PATEu-r ems-E CHARLES A. HENRY, OF WEST BURLINGTON, AND CARL A. OPPFELT, OF BUiRIiINGTON,

. "IOWA METHOD AND APPARATUS FOR FORMING- AROH TUBES Application filed April 29,

Our invention relates, in general, to an improved method of, and means for, bending pipes to predetermined shapes. It relates more in particular to a method of, and means for, producing arch tubes for locomotive fire boxes.

The so-called fire arch of present day locomotives is formed of fire bricks supported on tubes disposed longitudinally of the fire box, the tubes being in the nature of fines, since they are filledwith water and take up an appreciable amount of heat from the burning fuel. These arches are of various shapes, depending upon the design of the locomotive, and, of course,a different style ofarch tube must be employed in each case where the fire arch is modified. Since the tubes are in the nature of flues, they must be bent very accurately to avoid the formation of flat spots or the like, which would prevent the passage of a flue-cleaning machine, and the dimensions and radii of the various bends are very important, since they control the curvature of the arch, which curvature is also of extreme importancein properly controlling the burning fuel gases. Heretofore,

arch tubes of the character described, have I always been bent byhand methods to correspond to a previously produced template, with the result that the production of such tubes has been unsatisfactory,expensive and slow. I

Accordingly, the principal object of our present invention is the production of an improved method of, and means for, producing tubes of the character set forth. Another object is the production of improved and more uniformly accurate arch tubes. Another object is to produce arch tubes more quickly and more economically. Another object is the production of mechanism which may be operated with previously produced plans, whereby perfect arch tubes may be produced without the use of any kind of a template. Qther objects and features of the invention will be apparent from a consideration of the detailed description, takenin connection with the accompanying drawings, wherein Fig. 1 is a front elevational view, showing 192s. se ial ze. 359,143.

one embodiment ofthe tube-forming mechanism in elevation; i

Fig. 2 is a plan viewof the mechanism shown in Fig. 1;

' Fig. 3'is a longitudinal irregular section taken along the line 3 -3 of Fig. 2; i

Fig. 4 is an end view; l Fig. 5 is avertical transversesectiontaken on the line 55 of Fig. 3 f i Fig. 6 is an enlarged elevational view, as seen from the line 6-6 of Fig. 2, looking in the direction of the arrows;

Fig. 7 is a view looking at the end of Fig. 6;

Fig. 8 isa fragmentary somewhat schematic view showing the-way the mechanism is operated, and illustrating one. of the steps of the method;

' Fig. ,9 is aview similar toFig. 8 but show-- ing the use of auxiliary. equipment andillustrating one of the final steps of the method;

Fig. 10 shows: an arch tube, which is fairly representative of the type of bendemployed F ig- 11 shows the manner inwhichthe pipelor tube is marked in accordance with. the preliminary steps of the method; and

Fig. 12 shows. a portion of a chart which is employed as a guide in carrying out the method, and. in the use of the machine.

It is believed that the details of themethod will be understood from a consideration of the fmechanism withwhichis is practiced, but'we shall first set forth the general features .of the method, so; thata better. understanding. of the purpose ofthe machine may be had.

An arch tube21, as shown in Fig. 10;,1's provided with. a compound curvature, but the general nature of all arch tubes is somewhat the same. The ends,.as indicated at C and D, are generally turned at a somewhat sharp (Fig. 12) bythe charact'erA. The bentportion. B of the tube begins, at this point E,i

and from the point E to the other end of the tube, this entire distance is referred to on the chart by the character B.

Each different tube we designate by a certain class, but each type of tube is analyzed to locate the various bends and is marked ofl by the spaces indicated by the characters A, B, C and D. e first formthe portion B in a series of successive bends, by feeding the tube forward the same distance at each stroke of the bending tool, but so control the extent of movement of the bending tool as to produce the type of bend required in each case. As a preliminary step, we employ a marking device 23 which has a series of transverse slots 24, through which suitable marks may be made on the tube. l/Ve take the tube, measure the distance A thereon, which is shown by the chart for the type of tube to be made, set the end of the marking device 23 adjacent the mark E, which is the end of the space A, and then mark o'rlion the tube the number of strokes which will be employed to produce the requisite bend for the portion B, this also being determined by the chart.

Since with the mechanism we employ, the bending stroke results from the actuation of an air piston, we regulate the length of stroke by inserting a suitable stop or block in the path of the piston rod or cross-arm secured thereto, and so the length of the stroke is regulated automatically. f we were performing the method strictly by hand, the length of stroke would be given on the chart, but, in place thereof, we provide blocks of various widths, and the proper width block is shown in the chart and is selected for use on the machine. In the actual carryin out of the method, we employ the ma crime by means of which the tube is fed forward the proper distance by a single automatic operation, and since the stroke of the piston is con trolled, all that is necessary to produce tl e proper bend is to repeat the operation the proper number of times, as the chart sets forth. The final step in the actn l production of the tube is forming the bends C and D, and this we do quite quickly and readily on the machine, as will be set forth.

Referring now to the drawings in which the details of the machine are shown, we employ a frame consisting of an upper table 26 and a lower table 27, supported by uprights 2828, the table 26 being supported partly by uprights 29 29 and partly by blocks 31 disposed on the table 27. The tube is adapted to be bent around a semi-circular form 32, secured to the table by bolts SEE-33, in cooperation with a sheave-like roller 34, rotatably secured to the movable end of a twopart arm 36, which two-part arm is disposed at top and bottom of the semi-circular member 32 and is pivoted at 37. The tube is supported between the member 32 and a co-acting support 88, which has its end face 88 shaped to correspond to the outer circular shape of the tube, and since the member also has this same shape, the two members together form a complete circle for the support of the tube as it is bent. In order to maintain the tube in proper position, so that the bend will be made in the same plane throughout, we employ a special shape of end-supporting table 39 (Fig. 2), so that, no matter how great a bend the tube takes, it will always engage a portion of this small table.

[is to the actuating means, we support a cylinder 41 on the lower table 27, in which a piston 42 is reciprocable and is provided with a piston rod 43 ith a cross-head 44 secured to its outer end, the cross-head being slidable on the table An extension rod 46 pivotally securedto the cross-head by a pin 47, and this extension rod is provided with bifurcations 48 engaging around the pivoted arm 36 and provided with a pin which forms a pivot for the bifurcated end of the rod extension, and a bearing for the sheave-like roller 34. The lower surface of the cross-head 44 is provided with an opening 51, in which a block is adapted to be placed for regulating the stroke of the piston. The cylinder 41 is secured to the lower table 27 by bolts 53, and is braced with respect to the upper table 26 by bracing members 54, one end of which is secured to the table by bolts 56, and the other end secured to a cross-piece 57.

We preferably operate the piston 42 by means of compressed air, and, in order to admit air to either side of the piston, we provide pipe connections 58 and 59, each connected with a suitable control valve 61 operated by a lever 62. This lever is connected through suitable mechanism to be operated by foot-pedals 63 and 64, the pedal 63 being disposed at the enc. and one side of the table, while the pedal 64 is at the opposite end and opposite side. Accordingly, independent of which end of the tube the operator is grasping, he can control the movement of the piston. Any suitable system of rods and levers may be employed, connected with the foot-pedals 63 and 64, a conventional arrangement being shown, by means of which very satisfactory results have been obtained.

Vi e have previously described how the tube is fed forward a predetermined distance after each stroke of the piston. Figs. 6 and 7 show in detail the manner in which this feeding movement is accomplished. An extension plate 66 is secured to the side of the table and has fastened to a depending portion 66 thereof, the lower end of a lever 67 pivoted on a bolt 68 and having secured at an intermediate point a cross-piece 69, to which a horseshoe-shaped gripping member 71 is pivoted. A spring 72, secured to the gripping member and having its opposite end secured to an extension 73, holds the gripping member in a position to engage the tube asit is driven forward. A stop for the lever 67 is provided by a bolt 74, secured in a projection 76, the stop being so arrangedthat the proper length of stroke automatically takes place. To prevent the lever 67 being moved too far in the opposite direction, a fixed sto 77 is provided. By regulating the position of the bolt 74, and then moving the lever 67 the full distance between the two stops, the pipe is automatically fed the proper distance each time.

For producing the small bends at the ends of the tube, a separate attachment, shown in Fig. 9, is employed. This is in the shape of a rod 78 having a horn 7 9 at one end thereof, and having the opposite end in the shape of a narrower shank 81, threaded to receive a nut 82, and having an unthreaded portion which is disposed in the end of an arm 83 and secured bya bolt 84, threaded into a second arm 86. The two arms 83 and 86 are extensions of a supporting member 87, which is pivoted at 88 and is adapted to extend upwardly out of the way (Fig. 2)' when the member 78 is not in use. For determining the position of the bend resulting from the use of the horn 7 9, a bushing 89 is used, this bushing being of any suitable length, and being itself adapted to be positioned by turning the nut 82. The member 38is provider with marked graduations, as shown in Fig. 2, so that, to determine the location of the short bend, with the horn 7 9 in place and the tubeextending over it, the end of the tube is brought to the proper mark, or rather, the proper location is first determined by positioning the bushing 89 in the same way, and then all that is necessary is to insert the tube 21 and actuate the piston to make the bend.

The shaping of the tubes, while performed on the machine, is determined from plans previously engineered, and preferably by performing the various steps in the production of the tubes in a proper sequence. As shown in thechart in Fig. 12, which is, of

' course,simply illustrative, as the chart is much more complete, taking into consideration all types of tubes employed on various engines on a single railroad, the railroad in which this particular chart was worked out being the Burlington;

Assuming that tubes are to be made for a Class F-l engine numbered 540, the chart discloses that this takes a Type Number 3 of arch tube. On a separate blue print, We show the various types of tubes marked out as shown in Fig. 10. Assume that the tube shown is a Type 3 tube. The first step in the production of the tube is the selection of proper tube stock of sufiicient length. 'Me'asuring from-one end the distance A, up to the mark E, as set out, this distance being shown,

by consulting the chart, to be sixty-nine inches. The marking member 23 is then laid over the tube with one end located at the point E, and the other end extending toward the D end of the tube. Again consulting the chart, it is found that five strokes are neces sary to produce the proper bend, and accordingly five marks are placed on the tube through the slots 24-, successive and adjacent slots being used, starting from the left. In actual practice, we locate these slots three inches apart, but another distance could be selected and the method worked out on this basis.

With the tube markedin this way, it is inserted into the machine from the left of Fig. 2, the piston being in unactuated position and the sheavedike roller being in the position shown in dotted lines in this figure. The feedingmechanism, including the lever 67, is mounted in'place at this time, and when the first mark on the tube is brought to suitable position along the scale at 38 the gripper 71 is placed around the tube and it is ready to be fed forward- Before actual operation of the machine, however, the chart is again consulted, to determine the stroke of the forming piston. Consulting the chart again, it is found that a block is employed to obtain a 36 radius, and a block so marked is selected and this is inserted beneath the cross-head to limit the stroke of the piston. The piston and feeding mechanism are then alternately actuated for the proper number of strokes, and the proper curvature and leiigth' of curvature in theportion B is thenobtained.

When the curvature of'the portion B has been accomplishedsatisfactorily, the bending I ofthe tube is completed by forming the bends C and D. The tube is withdrawn from the machine,,and the feeding mechanism removed from the extension 66. The member 87 is then brought down into position, and the member 7 8 is secured in the -arms-83 and 86. The chart is consulted to determine the length of the bend C, and the regulating devices are so controlled that. the left-hand end of the bushing 89 (Fig. 9) is at a point on the scale 88* corresponding to the length ofthe portion C. The tube is then inserted over the horn so that its end abuts the end of the bushing in the manner shown, and by selecting the proper block to limit the stroke, this also being shown in the chart, and placing itin position, the actuation of the piston then automatically produces the proper bend. The same routine is carried out in connection with the production of the bend D.

'VVhen operating the machine and carrying out the method, there are generally sufficient tubes in process of making, so that asingle step in the process may be carried on on a number oftubes at one time, and so, more efficient operationobtained. The tubes are set out according to type and the distance A measured, and the requisite number of marks made on the tubes. They are then inserted in the machine seriatim and the bend B produced for all the tubes. The feeding device is then removed from the machine, and the horn-bearing member 78 secured in position, after which all. of the tubes are given the end bend, this also being carried on in such a ay to simplify the method.

lVhile the tubes are not bent in a definite and well defined curve along the radius set out, they are given a succession of slight bends three inches apart, and the over all effect is the same as it a true and continuous curvature were produced. The blocks employed in producing the bend B are marked according to the radius on which the bend is made, being marked for example 36 inches, 96 inches, 120 inches or the like. The blocks employed for making the bends C and D are simply marked according to the width of the block, and this may be from a traction of an inch up so that the length of stroke can be controlled in any way. Sometimes the bend is made without any block at all, sometimes with a large block in which a slight bend produced, and sometimes no bend at all is employed on the end. For example type 3 tube employs no G bend but the D bend is (3 inches from the end of the tube and a (3 inch block employed so that a bend is produced which is neither very acute nor very slight, but midway between the extremes. The horn around which the short bends are made is so shaped that no matter how sharp the bend, a perfectly circular cross section is obtained throughout.

lVe have described all of the details and features of our improved method and mechanism to enable those skilled in the art to practice the same, but it is obvious that we do not restrict ourselves necessarily to the details set out, the invention being limited only by the scope of the appended claims.

Vhat we claim as new and desire to protect by Letters Patent of the United States is 1. The method of forming arch tubes having short end bends and relatively long intermediate bends which. comprises marking oil the beginning of the long bend and forming a series of successive marks along the region of the bend definite equal distances apart, bending the tube a number of times equal to the number of marks by placing the mark at a predetermined definite position on a forming die, the radius of the bend being controlled by limiting the movement in the forming stroke, and finally making the end bends and controlling the angularity thereof by limiting the movement during the formin g stroke.

A forming machine for producing long intermediate bends and short end bends for locomotive arch tubes, said machine including a table, a semicircular forming die on the table having its edge concaved to correspond with the shape of the curvature Off the tube, a holding member having its end surface also curved to grip the tube and disposed at an angle so as to grip the tube between. said die and holding member, an arm pivoted at the center of curvature oi? said forming die, a sheave-like roller secured on the free end of the arm, an actuating piston and piston rod, a cross head on the end of the rod, and a connection between the cross head and sheavelike roller whereby said sheave-like roller may be advanced to bend the tube around said forming die.

3. A forming machine for producing long interme t bends and short end bends for locomotive arch tubes, said machine includin a table, a semicircular forming die on the table having its edge co'ncaved to correspond with the shape of the curvature of the tube, a holding member having its end surface also curved to grip the tube and disposed at an an gle i as to grip the tube between said die and he ding member, an arm pivoted at the center oi? curvature 01? said forming die, a sheave-like roller secured on the :tree end of the arm, an actuating piston and a piston rod, a cross head on the end oi the rod, a connection between the cross head and sheavelilte roller whereby said sheavedike roller nay be advanced to bend the tube around said forming die, and means for limiting the movement of the piston in accordance with the radius of curvature required the tube.

l. A forming machine for producing long intermediate bends and short end bends for locomotive arch tubes, said machine including a table, a semicircular forming die on the table having its edge concaved to correspond with the shape of the curvature of the tube, a holding member having its end surface also curved to grip the tube and disposed at an angle so as to grip the tube between said die and holding member, an arm pivoted at the center of curvature of said forming die, a sheave-like roller secured on the free end of the arm, an actuating piston and a piston rod, a cross head on the end of the rod, connec tion between the cross head and sheave-like roller whereby said sheave-like roller may be advanced to bend the tube around d forming die, and means for advancing the tube a predetermined distance after each stroke.

5. A forming machine for producing long intermediate bends and short end bends for locomotive arch tubes, said machine including a table, a semicircular forming die on the table having its edge concaved to correspond with the shape of the curvature of the tube, a holding member having its end surface also curved to grip the tube and disposed at an angle so as to grip the tube between said die and holding member, an arm pivoted at the center of curvature of said forming die, a

sheave-like roller secured on the free end of the arm, an actuating piston and a plst-on rod, a cross head on the end of the rod, a connection between the cross head and sheave-like roller whereby said sheave-like roller may be advanced to bend the tube around said forming die, meansior limiting the movement of the piston in accordance with the radius of curvature required in the tube and means for advancing the tube a predetermined distance after each stroke.

6. A forming machine for producing long intermediate bends and short end bends for locomotive arch tubes, said machine including a table, a semicircular forming die on the table having its edge concaved to correspond with the shape of the curvature of the tube, a holding member having its end surface also curved to grip the tube and disposed at an angle so as to grip the tube between said die and holding member, an arm pivoted at the center of curvature of said forming die, a sheave-like roller secured on the free end of the arm, an actuating piston and a piston rod, a cross head on the end of the rod, a connec-, tion between the cross head and sheave-like roller whereby said sheavelike roller may be advanced to bend the tube around said forming die and an end supporting table disposed to support the bent end of the tube so that successive bends thereto will be in strictly the same plane.

7. A forming machine for producing long intermediate bends and short end bends for locomotive arch tubes, said machine including a table, a semicircular forming die on the table having its edge c-oncaved to corres ond with the shape of the curvature of the tu e, a holding member having its end surface also curved to grip the tube and disposed at an.

angle so as to grip the tube between said die and holding member, an arm pivoted at the center of curvature of said forming die, a sheave-like roller secured on the free end of the arm, an actuating piston and a piston rod,

a cross head .on the end of the rod, a connection between the cross head and the end of the rod, a connection between the cross head and sheave-like roller whereby said sheavelike roller may be advanced to bend the tube. around said forming die, means for limiting the movement of the piston in accordance with the radius of curvature re quired in the tube, means for advancing the tube a predetermined distance after each stroke and an end supporting table disposed to support the bent end of the tube so that successive bends thereto will be in strictly the same plane.

8. A forming machine for producing long intermediate bends and short end bends for locomotive arch tubes, said machine including a table, a semicircular forming die on the table having its edge concaved to correspond with the shape of the curvature of the tube,

a holding member having its end surface also curved. togrip the tube and disposed'at an angle so as to grip the tube betweensaid die and, holding member, an arm pivoted'at the 7 center of curvature of said forming die, a

sheavedike roller secured on the free endof the arm, an actuatingpiston and a piston rod,

a cross head on the end of the rod, aconnec tion betweenthe cross head and sheave-like, roller whereby said-sheave-like roller maybe advanced to bend the tube around said forming die and a separateforming member for preserve thecircular character of the tube at the location of the bend.

9.- A .forming machine for. producingilong intermediate .bends and short end bends for locomotive arch tubes, said machine including atable, a semicircular forming. die on the table havingits edge concaved-to correspond withthe shape of thecurvature ofzthe tube, aholding memberihavingits end surface. also curved to grip the tube and disposed .at-an anglesoias to grip the tubebetween said die and holding memebiyan arm pivoted at the centerof' curvature of said forming die, a sheave-likerol1er secured on the free end of the arm, an actuating piston and a piston rod, across head on the end of the rod, a' connection between the'crosshead and sheave-like roller whereby said sheave-like rollenmay be advanced'to bend the tubearound said forming die, and-a separate forming member for producingsharp bends at the ends of the tube, said forming member disposedialong.theaxis of the tube, andhaving a horn fat the endthereof shaped to cooperate with the forming die and sheavelike bending roller to preserve the circular character of the tube atthe location'of the bend, means being provided for supporting the special bendingtool, and said tool having a threaded shank provided with a nut by means of which the location of the end bendis controlled. 1 v i 10. A forming machine for producing longintermediate bends and short end bends for locomotive arch tubes, saidmachine includingra table, a semicircular forming die on the table having its edge concaved to correspond roller may be advanced to bend the tube around said forming die, means being pro vided for supporting a special bending tool, and said tool having a threaded shank provided with a nut by means of which the location of the end bend is controlled, the special forming tool being adapted to receive a bushing for limiting the extent to which the tube can be extended over said forming tool, and the holding member being graduated to indicate the location of the bend in the tube from the end thereof.

11. A forming machine for producing long intermediate bends and short end bends for locomotive arch tubes, said machine including a table, a semicircular forming -die on the table having its edge concaved to correspond with the shape of the curvature of the tube, a holding member having its end surface also curved to grip the tube and disposed at an angle so as to grip the tube between said die and holding member, an arm pivoted at the center of curvature of said forming die, a sheave-like roller secured on the free end of the arm, an actuating piston and a piston rod, a cross head on the end of the rod, a connection between the cross head and sheave-like roller whereby said sheavelike roller may be advanced to bend the tube around said forming die, a separate forming; member for producing sharp bends at the ends of the tube, said forming member disposed along the axis of the tube, and having a horn at the end thereof shaped to cooperate with the forming die and sheavelike bending roller to preserve the circular character of the tube at the location of the bend, the means being; provided for supportin; said special forming tool and said supporting means removable to allow room for the tube during the formation of the relatively long intermediate bend.

12. A forming machine for locomotive arch tubes comprising; a die of definite curvature, a roller cooperating with said die to form a bend in said tube, means for moving said roller a predetermined distance to form a bend of predetermined length, and means for advancing the tube a predetermined distance to definitely space a series of such bends, whereby the total curvature of the tube is determined.

In witness whereof, we hereunto subscribe our names this 9th day of April, 1929.

CHARLES A. HENRY. CARL A. OPPFELT. 

